sysdeps/unix/sysv/irix4/start.c

   1 /* Copyright (C) 1991, 1992 Free Software Foundation, Inc.
   2 This file is part of the GNU C Library.
   3
   4 The GNU C Library is free software; you can redistribute it and/or
   5 modify it under the terms of the GNU Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 License, or (at your option) any later version.
   8
   9 The GNU C Library is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #include <ansidecl.h>
  20 #include <errno.h>
  21 #include <stdlib.h>
  22 #include <unistd.h>
  23
  24 #ifndef __GNUC__
  25   #error This file uses GNU C extensions; you must compile with GCC.
  26 #endif
  27
  28 /* The first piece of initialized data.  */
  29 int __data_start = 0;
  30
  31 VOLATILE int errno = 0;
  32
  33 #ifndef HAVE_GNU_LD
  34 #undef  environ
  35 #define __environ       environ
  36 #endif
  37
  38 char **__environ;
  39
  40 extern void EXFUN(__libc_init, (int argc, char **argv, char **envp));
  41 extern int EXFUN(main, (int argc, char **argv, char **envp));
  42
  43 /* Use the stack pointer to access the arguments.  This assumes that
  44    we can guess how big the frame will be.  */
  45 register long int sp asm("sp");
  46 #ifdef __OPTIMIZE__
  47 #define STACKSIZE 8
  48 #else
  49 #define STACKSIZE 10
  50 #endif
  51
  52 void
  53 DEFUN_VOID(__start)
  54 {
  55   int argc;
  56   char **argv, **envp;
  57
  58   /* Set up the global pointer.  */
  59   asm volatile ("la $28,_gp");
  60   argc = ((int *) sp)[STACKSIZE];
  61   argv = (char **) &((int *) sp)[STACKSIZE + 1];
  62   envp = &argv[argc + 1];
  63   __environ = envp;
  64
  65   __libc_init (argc, argv, envp);
  66   errno = 0;
  67   exit (main (argc, argv, envp));
  68 }